Lens modules for one time use cameras and other optical devices are commonly made by assembling lens components, such as optical elements and aperture stops into a holder and attaching a retainer to hold the lens components in place. The assembly can be manual or automated. In both cases, mistakes can be made as to the orientation of individual optical elements. Such mistakes can occur during placement in the lens module or during an earlier step. For example, an individual lens element can have been positioned upside down in a rack or the like, which feeds an automated assembly tool. Once the lens module is assembled, it is not immediately apparent that one or more optical elements may have been reversed. Optical testing and other methods can be used to determine if the placement is correct. These methods tend to be cumbersome and add cost.
It would thus be desirable to provide improved lens module assembly methods and assembly intermediates, in which incorrect lens placement can be simply and easily prevented.